Summary of N1K1-J allied flight test evaluation:

Rudder trim controls were excellent, but elevators were too light and ailerons too heavy (over 360 mph especially), so controls were unbalanced. The stick was too far forward and high for comfort. Controls for flaps, wheels and brakes were not desirable but cockpit vision was good.

Stall was 100 mph clean. If cowl flaps were closed, a serious port wing stall came without warning resulting in accelerated stall and risk of inverted spin.

Dive speed was high. It rolled and turned well for its size, but immelmans were sloppy.
It didn't handle with the confidence inspiring stability of say, a J2M Raiden.

The later N1K2-J Kai was an improvement, addressing many of the faults of the N1K1-J in this flight test.

Gerhard,
I hadn't heard anything about the the cannons on the Shiden jamming. Can you explain? Maybe it's only when fired in turns where all planes with wing cannon had this tendency.
Beyond that, I would appreciate more info.

One of Japans top 3 fighters. I would say A6M, KI-84, N1K2 in that order, I rate it that way considering all aspects of aircraft mentioned. N1K2 had 3 main problems, weak landing gear, engine problems, and guns prone to jamms. If the plane worked perfectly, it may have been the best Japan produced. Over all I would rate the plane at a 8.5 rating.

I can perhaps excuse it with US pilots misidentifying them as Tojos or something but that's embarrassing to me. I simply can't believe that.

The oft mentioned combat of Muto in the above text begs comment.
It is more accurate to add that he was not alone. N1Ks and F6Fs of comparable numbers were engaged and he did have 4 victories as related but his unit had his back.

Gus,
It was a great book for it's time. I read it in the 60s. I venture to say I'm not the only one here who already read it.
Today it has its detractors (not directed at Sakai so much as the co-author). This is true of many books from that period, like William Green's series, etc...

read Saburo Sakai's book, 'Samurai' which mentions this particular plane and nearly all the other Japanese fighters.....

read Saburo Sakai's book, 'Samurai' which mentions this particular plane and nearly all the other Japanese fighters.....

If VF-85 lost 8 or 9 F4Us in 2 fights with N1Ks in June 1945, and only 3 Georges were lost, why are these not in the US Naval win-loss records? That's about 3 to 1 ratio in favor of the Shiden.
I can perhaps excuse it with US pilots misidentifying them as Tojos or something but that's embarrassing to me. I simply can't believe that.

1 kill vs 3 loss ratio was the confirmed record of Genda's outfit in the last months of WW 2. That's counting the Allied fighters of all types, not just US Navy and Marines where they had parity. It doesn't count ordinary N1K Shiden outfits.
So Spitfires, P-51s, and P-47s must have done better against Genda and his elite group of pilots than the US F6Fs, FMs, and F4Us did.

I am mystified by the lack of loss the USN records to the N1K Shiden 'George'. Historians credit the crack IJN 343rd with near parity of 1 to 1 ratio more or less vs the VF-82, -9, VBF-17, -VMF-23 between 12/1944 and 3/1945 and others in April. US Navy says 35 Shidens were shot down without loss to US Navy fighters 1944-45. Granted other less skilled Shiden outfits would score less than these did. Does anyone have the answer for the discrepancy? Perhaps unidentified or misidentified Japanese fighters were credited. The overall Shiden ratio is perhaps 13 losses per victory like the A6M according to Wikipedia.

An ideal plane for dogfihts!

I found another detail online: In tight turns, if the stick were handled roughly the N1K1-J might flip over and auto rotate making it not so pilot friendly. Then he could lose control and spin. I still don't know about the Kai.
Still it could out turn a Hellcat if the pilot took care, due to its combat-flap system in addition to it's wing-loading edge. But a good F6F pilot could still get in a burst early.

I was reading Pacific Fighters by Flight Journal about the George. Aces of the fighter were commenting on the N1K1-J tendency to autorotate. This handling problem could lead to an uncontrollable spin. Was this related to being tail heavy? With the N1K2-J redesign, I wonder if that fault was addressed successfully.
If anyone is familiar with this (with any fighter), any info would be welcome.

the N1K Shiden was truly a deadly opponent to the Allied fighters such as the F6F Hellcat and the F4U Corsair. It was one of the finest Japanese fighters of World War II. It was originally designed as a floatplane fighter but by 1943 aircraft of this type were not needed anymore. It has 4 20mm cannons and good armor protection. It will have been a very effective bomber destoryer had it not have a poor rate of climb and reduced engine performance at high altitude.

I see the 3 view drawing is the N1K1-J Shiden 11 with the triangular tail fin and the 2 cannon boots. Just over a thousand were built.
The photo is the later NiK2-J Shiden-Kai 21 with the lower set wings with all 4 wing cannon internally mounted. Just over 400 were built.
It was the result of Kawanishi deciding to go ahead as a private venture based on it's promising performance as a land based version of the Kyofu (Rex) floatplane fighter.
It was a timely decision and in the end of 1943 N1K1-J production was authorized by the Imperial Navy. The Zero's torch had been passed.

N1K2 best roll-rate was 82 deg/sec at 240 mph;
76 200 mph;
74 350 mph.
A6M2 " 57 100- 150 mph (for comparison).
32 340 mph
F4F-3 " 69 240 mph
F6F-3 " 68 280 mph
F6F-5 " 91 300 mph
F4U-1D " 108 "

Allied test pilots were taken by the George, summarizing it as the finest fighter-bomber in the Pacific bar none!
The Japanese felt they could fly circles around Hellcats with it. Surprisingly maneuverable and having all-around view like the A6M6 Zero but with double the high velocity punch and well protected - a bit like the cannon armed Corsair (except the U.S. Hispano 20mm was prone to jam).

To Japanese Zero pilots used to pure offense, never expecting to take a hit, a big heavy complex Shiden may have seemed a lot like Western design philosophy. Armor plate protection, loaded weight approaching 10,000 lbs, engine teething troubles - what a contrast to the simple and proven A6M. Others obviously saw that the battle had changed and the Shiden was the best answer the IJN had. And for it's size it was plenty agile thanks to combat flaps and about 2,000 hp!
IT's speed and roll-rate was more competitive than that of the Zero. And firepower? 4 slow but powerful long range 20mm wing cannon to deal with well protected US Corsairs and Thunderbolts. Maybe not produced in the numbers of it's army counterpart, the Hayate, it certainly eclipsed it's stablemate, the Raiden in production. Climb rate for the N1K1-J was 3,300 ft/min. For the N1K2-J it ranges from 3,600 to 4,000 ft/min. Its like a P-47 that's light on its feet. These late-model Japanese fighter-bombers had power loadings and wing loadings that most US planes lost somewhere between their prototype and their overweight fighter-bomber models by the last year of the war.

Kensuke Muto was quite a fighter Pilot, but not all the 'old hands' liked the Shiden! A lot Zero jockies strenuously resisted transfer to Genda's Shiden equipped oufits!